# AEI1: TRANSIDERR not handled Source: https://wndsoftware.com/mainframe-errors/aei1 ### AEI1: TRANSIDERR not handled An AEI1 abend means an EXEC CICS START command named a transaction ID that CICS doesn't have defined, and the program didn't handle the TRANSIDERR condition. Usually the transaction isn't installed in that region or the program passed a wrong name. #### Other names for this code Also written as `AEI1 abend`, `CICS AEI1`, `abend AEI1`, `TRANSIDERR`, `CICS TRANSIDERR`, `AEI1 TRANSIDERR`, `START TRANSID error`. ### What it means EXEC CICS START asks CICS to run a transaction, now or later, often with data passed through FROM or a channel. CICS checks the TRANSID when the START is issued. If no transaction with that ID is defined, CICS raises TRANSIDERR. EIBRESP is 28. IBM lists two more cases. A transaction defined with DYNAMIC(YES) raises TRANSIDERR when its REMOTESYSTEM isn't the local system. A dynamic routing decision that sends the request to the local system can also conflict with REMOTESYSTEM and raise it. Some failures don't raise TRANSIDERR. If the transaction is defined but it or its program is unavailable when CICS later tries to start the task, the START itself already completed without error, and the task just never runs. A START for a task on a remote system doesn't return error conditions to the program either. The default action for TRANSIDERR is to abend the task with AEI1. A program that codes `RESP(WS-RESP)` gets control back and can test for `DFHRESP(TRANSIDERR)`. ### Common causes - The transaction is new and was defined in the CSD, but the group wasn't installed in this region or isn't in its group list. - The TRANSID field holds the wrong value. It may be lower case, contain low-values, or come from a table or parameter that is out of date. - The program was moved from one region to another, and the target region doesn't define all the transactions it starts. - The transaction is defined with DYNAMIC(YES) and a REMOTESYSTEM that doesn't match how the request is routed. ### How to find the problem - The terminal message `DFHAC2206` names the failing transaction. In the dump, EIBFN shows the START and EIBRSRCE the transaction ID it asked for. - Run `CEMT INQUIRE TRANSACTION(xxxx)` with that ID. If CICS doesn't find it, the transaction isn't installed in this region. - Use CEDA to look for the TRANSACTION definition in the CSD and find which group holds it and whether that group is in the region's group list. - Run the issuing transaction under CEDF to see the TRANSID value in hex on the START. ### How to fix it - Install the transaction definition in the region, and add its group to the group list so it is there after the next cold start. - Correct the TRANSID the program passes. Check upper case, padding and where the value comes from. - Handle TRANSIDERR in the program. Log the bad ID and tell the user instead of abending. - For DYNAMIC(YES) transactions, review REMOTESYSTEM and the routing program so they agree. ### What it looks like ```text DFHDU0203I 10/18/2026 08:03:19 CICSPRD1 A transaction dump was taken for dumpcode: AEI1, Dumpid: 1/0103. DFHAC2206 08:03:19 CICSPRD1 Transaction SCH1 failed with abend AEI1. Updates to local recoverable resources backed out. ``` ### IBM documentation [IBM documentation: AEI1](https://www.ibm.com/docs/en/cics-ts/6.x?topic=codes-aei1). Use the documentation for your installed release. [Report a correction to WND Software](https://wndsoftware.com/contact#message). Last reviewed 2026-10-18 by the WND Software team. Written in our own words. For the full reference, check IBM’s CICS documentation for your release. ### Related codes [AEI0 PGMIDERR not handled Read →](https://wndsoftware.com/mainframe-errors/aei0) [APCT Program not found in CICS Read →](https://wndsoftware.com/mainframe-errors/apct) [AEI2 ENDDATA not handled Read →](https://wndsoftware.com/mainframe-errors/aei2) [AEYH QIDERR not handled Read →](https://wndsoftware.com/mainframe-errors/aeyh) [AEIP INVREQ not handled Read →](https://wndsoftware.com/mainframe-errors/aeip) ### Questions #### The started task never ran, but there was no AEI1. Why? If the transaction is defined but it or its program isn't available when CICS tries to start the task, the START has already ended normally. Look for messages about the task failing to start instead. #### What is the difference between AEI1 and APCT? AEI1 means the transaction ID isn't defined. APCT means the transaction exists but CICS couldn't find or load its program. #### Does a START to another region return TRANSIDERR? IBM notes that error conditions aren't returned for tasks started on a remote system, so the issuing program won't see it there. [CICS transaction abends](https://wndsoftware.com/mainframe-errors/cics-abends) · [AEI0](https://wndsoftware.com/mainframe-errors/aei0) · [AEI2](https://wndsoftware.com/mainframe-errors/aei2) [← All error codes](https://wndsoftware.com/mainframe-errors/)